The Benefits and repercussions of the use of mobile phones in a third world country: El Salvador

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Introduction

The Benefits and repercussions of the use of mobile phones in a third world country: El Salvador

Introduction

The widespread of the use of mobile phones in El Salvador is a very recent phenomenon, dating itself from its growth in the year 1997. Their use has increased in the past decade. Now making them an indispensable tool in business, commerce and for regular society too. From recent studies, it has been deduced that by April 2001, there were approximately three to three million and a half of mobile phones in circulation in the country. This in an equivalent of one phone for every 3 people. Two of the main companies providing the service are from Telefonica (MoviStar) and Telemovil de El Salvador.

The extensive use of this device had leaded not only in the country but also worldwide the concern and public debate about the effects on human health. The concern focuses deeply in the context of the emissions of radio frequency radiation (RF) from both the mobile phone itself and the base station that provides the signal to the device. The levels of exposure

First of all in order to analyze the issue stated above, more about RF fields from mobile phones have to be explained.

Mobile phones and their base stations transmit and receive signals using electromagnetic waves. An RF wave used for radio communication is referred to as a carrier wave. The information it carries (speech, computer data, etc) has to be added to the carrier wave in some way, this is a process called modulation. The information can be transmitted via digital or analogue signals. The carrier wave varies much faster than the signal so that the modulation produces a relatively low oscillation in the amplitude of the carrier wave, This occurs if transmitted in the analogue form. The other way of transmission is by the digital form, concerning itself from ceros and ones. Digital transmission, usually binary, offers many technical advantages over analogue transmission systems. It is less at risk to distortion by interference and electrical noise, and moreover it is replacing or has completely replaced analogue transmissions in radio, TV and mobile phones. (see figure 1.2)

Concerning mobile phones, they send and receive information by radio communication.

From scientific evidence the electric and magnetic fields produced in the body by a nearby electromagnetic source causes both thermal and non-thermal biological effects. And again the effect vary with the emitted frequency of the wave, and tissues containing magnetite (Fe3O4) are being studied, as magnetite is a naturally occurring oxide of iron, and iron has electromagnetic properties induced if in a field. Magnetite is found in certain bacteria and in the cells of many animals. It has been found that animals like some species of birds and fish make use of the magnetite to provide them with magnetic sensibility, which they use in navigation. Moreover no other effects associated with electromagnetic interaction have been demonstrated in animals. Indeed it seems to be generally that any biological effect from the mobile phones is much likely to be from electric than from magnetic fields.

Looking more deeply into the effects, thermal effects are those who are caused by the rise in temperature produced by the energy absorbed from the oscillating electric fields.

Figure 1.1

Figure 1.2

Figure 1.3

[1] See annex 1

[2]

[3] www.webopedia.com

[4] Coherent time is the average time between random phase changes, which are the result of phase modulation.

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